AVM FRITZ! Troubleshooting Manual

Poor voice quality when conducting calls
When conducting calls, one of the following issues either occasionally occurs or always occurs:

When conducting calls, you experience disturbances such as echo, dropouts, delays or background noise.

A loud and annoying hiss is heard when conducting calls.

The voice of one or both parties sounds distorted or "choppy".
Simply proceed as described below. After each measure, check whether the problem is solved.
1 Installing the latest software for your telephone
1. Install the latest software
2 Disabling HD telephony on your ISDN line
The following steps are only necessary if you are using the FRITZ!Box on an ISDN line and you cannot
understand the other party when they speak (very distorted, extremely noisy, robotic voice, or static and
crackling can be heard).
1. Enter #962*2* on your telephone and press the call key (pick up the handset).
2. Hang up again after about 3 seconds.
Note:You can reenable HD telephony by entering #962*1*.
3 Restarting the FRITZ!Box
1. Click "System" in the
2. Click "Backup" or "Reset" in the "System" menu.
3. Click on the "Restart" tab (if available).
4. Click the "Restart" button.
4 Reducing the call volume on the telephone
1. Reduce the call volume on the telephone: Press the "down arrow" or "telephone book" icon on the
control ring while speaking on the telephone.
5 Registering cordless telephones with the FRITZ!Box
1. Register all cordless telephones
stations.
on the telephone.
FRITZ!Box user interface.
with the base station of the FRITZ!Box and switch off any other base